Electric traction system.



PATENTED APR. 30, 1907.

A. GHURGHWARD. ELECTRIC TRACTION SYSTEM. APPLICATION FILED JUNE 1,1906.

2: :3 33 w a 8 8 2 5 Fa E 2 G I nvenCBr. Alexander Churchword; by @91 M A y,

UNITED STATES PATENT orrron.

ALEXANDER OHURCHWARD, OESCHENECTADY, NEW YORK, AS SIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 61* NEW YORK.

ELECTRIC TRACTION SYSTEM.

Specification of Letters Patent.

ratenteo April 30, 1907.

Application filed June 1,1906. Serial No. 319,753.

To (til whont it may comm/'11 Be it known that I, ALEXANDER CHURCH- yman, a citizen of the Umte'd States, residing at Schenectady, county of Schenectady,

State of New York, have invented cert'ain new and useful Improvements in Electric Traction Systems, of which the following is a specification.

In transportation systems known .rackless trolley systems, wherein an elec trically-propelled vehicle running in the ordinary roadway receives; current from an overhead trolley, it is desirable to provide flexibility of operation such that the vehicle may leave the road adjacent which the trolleywire is situated and travel through roads branching from the main road.

The object of the present invention is to provide means wl'iereby such vehicles may be ,made to operate satisfactorily either when receiving current from the trolley or when operating on branch roads on which there are no trolleys.

To the above end the present invention contemplates the use of a motor apparatus on the vehicle arranged to propel the vehicle while operating on current received fronran external source of supply and, during such operation, to charge a local source of supply, such as storage battery; and thereafter to operate on current supplied from the storage battery to propel the vehicle independently of the external source of supply. The particular arrangement of'parts employed will of course vary greatly to meet different conditions, but where the voltage of the external source is high, as for example, where the vehicle is adapted to take current from a street railway trolley wire ,or other trolley wire carrying current'at, a similar potential, the mo tor apparatus should preferably be designed to operate on the high voltage of the external source and on a much lower storage battery voltage; since ordinarily it would not be practicable to have a storage battery whose voltage is as high as the voltage in street railway. systems. Therefore, in one of its forms, the present invention employs a motor having two separate armature windings and two eommutators, together with common field windings for the armature. windings, which field windings awconnected in series when parallel when operating on low potential current; one of the armature windings receiving current only from the external source and the other armature winding either receiving cur rent from or supplying current to the storage battery.

My invention comprises further features of construction and organization of parts to be hereinafter .described and particularly pointed out in the claims.

In the accompanying drawing I have illustrated a preferred form of the present invention adapted to systems employing a high external voltage and a much lower storage battery voltage.

In said drawings: Figure 1 .shows diagrammatically the entire equipment of one vehicle; Fig. 2 shows diagrammatically the main circuits when the vehicleis o )erating oncurrent received from the external source; and Fig. 3 is a diagram of connections when the Vehicle-is operating on current supplied from the storage battery.

Referring to the drawing, M indicates a motor having armature windings a and b and a plurality of field windings L is a source of current supply external to the-vehicle, such as a trolley wire.

T is a current collector carried by the vehicle and adapted to receive current from the trolley wire.

B is a storage battery on C is a'main controller.

K is a commutating switch arranged to connect the controller and motor either to thercurrent collector or to the storage bat terv.

The controller is illustrated as a reversing the vehicle.

controller of the ordinary rheostatictype.

positions, namely, thatposition wherein the upper row of rectangular contacts cngcp Assuming that it is desired to operate :he

The commutating switch has two running vehicle along the main road adjacent which the trolley wire is situated: the commutating switch is operated so as to bring the upper row of movable contacts into engagement with the fixed contacts and then, upon turning the controller to its first forward running position wherein the movable contacts engage with the fixed contacts along line 1 1, a circuit may be traced from current collector T to contact 5, of the commutating switch, through contacts 34, 36, .and 8, to contact 0 of the controller, movable contacts of the controller, through resistance R, contact 0', movable contact of the controller, contact 0, contacts 9, 37, 41, and 13, through the armature winding (1, contacts 14', 42, 38, and 10, cont-act c movable controller contacts, contact a contacts 15, 43, and16', through the upper section f of the field windings, through '20 contacts 17, 44, and 18, through the second section of field windings and thus by way of contacts 1.9 to 27 and 45 to 49, and contacts 51 and 29, through the remainder of the sections of the field windings in series with each other, to ground. The armature winding 0 isthereforeconnected in series with the field windings, all of which are connected in series with each other, and current issup'plied to these elements from the trolley wire through .the resistance R. Upon turning the controller successively. through its second, third and fourth running positions, the resistance is cut out step-by-ste'p, so that finally the armature winding a and the field windings are left connected directly across the line. A further circuit may be traced from the upper ,terminal of armature 5, through contacts 12, 40, 33 and 4, to contact a, movable controller contacts, contact c, to contacts 2, 31, 50 and 28, to the point as, and thence through the coil 0 of a relay 0 to a oint 4 through contacts 6, 35, 30, and 1, t rough contacts a", movable controllercontacts, contact 0 through contacts 3, 32, 39 and 11, to the lower terminal of armature winding 6. The contacts 0 of the relay, it will be seen, complete a circuit between the point IE and y in in shunt to the relay coil this circuit including th e storage battery and, if desired, a con trolling device D. The 'relay is so adjusted that the current'passing through it is insuliicient to operate it until the vehicle 'has reached such a speed that the voltage of armature winding 6 is sulliciently high to cause a charging current -toflow into the battery. As soon as the proper voltage is reached, the relay closes its contacts and current flows from the armature winding 7), through tie circuit previously traced, excep'tthat between ac and y the current divides, a portion passing through the coil of the relay and the remainder going through the storage ,b tteryj; The controlling device U is for" the purpose of cutting down-the charging current and consists of a rheootat cl, ann an operating electromagnet whose coil (1 is in series with the battery. The arrangement is such that when the charging cu'rrent becomes too large resistance is cut in and the current diminished.

in Fig. 2 I have shownthe various motor and battery connections when current is being received from the outside source; the vehicle being assumed to be running at a speed so low that the battery is disconnected from the armature winding b. Upon leaving the main road fora side, street or a branch road along which there is no trolley wire, thecommutating switch is moved into its other running position. The contacts 1 to 5, inclusive, and 13 and 14, are now idle, so that armature winding a is entirely out out and the current collector T is disconnected. Similarly, the circuit through the relay coil 0 is interrupted at contact 6, so that the relay andthe device D remain inoperative. Assuming the controller 0 to be again in its lirst running position, a circuit may be traced from the left-hand terminal of battery B, through contacts 7, 52 and 8, through contact (2, movable controller contacts, resistance R, contact c" movable controller contacts, contact 0, through contacts 9, 53, 55, 11, armature winding 5, contacts 12, 56, 54, 10, contact 0 movable contacts of the controller, contact 0, contacts 15 and 57, and thence by means of contacts 16 to 28 and 58 to 68, through. the

several sections of the field winding in parallel, to the right-hand terminal of the battery. Thus it will be seen that the armature wind.- ing 1) is connected in series with the several sections of the field winding connected in p arallel with each other, the whole being supplied with current from the battery through the resistance R. By turning the controller through its second, third and fourth positions the resistance R is cut out step-by-step and the motor is left connected directly across the battery, The 0 ierative motor circuit, together with the idle relay-circuit, during o -oration on current supplied by the storage battery, is indicated in Pig. 3.

The leads from the terminals of both arlna- I ture windings pass through the controller and the contacts oi the coi'itroller are so arranged that when the controller is moved toward the right instead of toward the left, the

,connections of these armature windings to the remainder of the system is reversed, whereby the proper circuit conditions are always maintained either for forward or reverse operation. I r

It will be seen that the storage battery is made to do only a minimum amount of work since the field of the motor is excited by current received from the external source when the vehicle is running along the main road and the storage battery is'em',':loycd for this purpose only when no o current is avail- By arrangh the coin? .tating switch as shown, there is no danger of damage resulting by bringing thecurrent collector into engagementwith the external source while the vehicle is being operated from the storage battery, since the storage battery is at all times entirely disconnected from the current collector.

Although I have illustrated and described my invention as embodied in a preferred form for use under certain conditions, I do not desire to be limited to the particular arrangement of parts shown, except as specifically indicated in the appended claims, since in its broader aspects the invention may take various forms and in the claims I intend covering all such forms;

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In an electric traction system, a vehicle, a source of current supply external to the ve hicle, a source of current supply on said vehicle,a dynamo-electric machine for propelling said vehicle having two armature windings and a field winding, and means for connecting one of said armature windings and said field winding'to oneof said sources and for connecting the other armature winding and said field Winding'to the other source.

2. In an electric traction system, a vehicle, a source of current supply external to the ve- "hicle, a source of current supply on said vehicle, a dynamo-electric,machine for propelling said vehicle having ,two armature windings.

. hicle, a source of current supply on said vehicle,a propelling dynamo-electric machine for said vehicle having two armature windings and a plurality ol' field windings, and means for connecting one of said armature windings and the field windings arrangedin series to one of said sources and for connecting the other armature Winding and the field windings arranged in parallel to the other source.

' 4. In an electric tractionsystem, a vehicle,

= a source of current. supply external to the vehicle, a storage battery on the vehicle, a propellingdynamo-electric machine on said veiicle having two armature windings and a plurality of field windings, and means for connecting one of said armature windings and the field windings arranged in series to said external source and for connecting the other armature winding and the field windings .arran ed in parallel to the storage battery.

5. v n an e ectr c traction system, a vehicle,

a source. of current supply external to the vehicle, a storage battery on the vehicle, propelling dynamo-electric machine on said vehicle having two armature windings and a plurality of field windings, and means for connecting one of said armature windings and the field windings arranged in series to the external source and the other armature winding to the storage battery and for disconnecting the first armature winding and the field windings from the external souiire and connecting the other armature winding and the field windings arranged in parallel to the battery.

6. In an electric traction system, a vehicle, a source of current supply external to the vehicle, a source of current sup )ly on the vehihicle, a propelling dynamo-electric machine on the vehicle having two armature windings and one set of field windings, and. means for energizing the field wind ings and one armature winding from one source or the field windings and the other armature winding hicle, a storage battery on the vehicle, apropelling dynamo-electric machine on there hicle having two armature windings and a plurality of field windings, and'means for arranging the field windings in one redation toward each other and energizing them and one armature .winding from the external source.or for arranging the field windings in other relations toward each other and energizing them and the other armature winding from the storage battery.

8. In an electric traction system, a vehicle, a source of current supply external to the \ehicle, a storage battery on the vehicle, a proelling dynamo-electric machine onsaid "eliicle having two armature windings and one set. of field windings, means i or energizing said field windings and one of said armature windings from the external source of current sup- )ly or for energizingthe of her armaturp windmg and the field windings from the storage battery in order to propel the vehicle, and means for automatically connecting one ar mature winding tothe storage battery upon predeterminedvoltage in that winding when the other armature winding and the field windings are energized from the externalsourcc.

9. In an electric traction system, a vehicle, a source of current supply external to the ve hicle, a storage battery on said vehicle, a propelling dynamo-electricmachine on said veiicle having two armature windings 35nd one set of field windings, and means for c eaner-ting one of said armature windings .to the storage battery in series with the fielo g wind ings arranged in parallel or for connecting the other armature winding to the external win lings from the other 50111-8 in source of supply in serieswith the field wind ings arranged in series.

10. In an electric traction system, a vehicle, a source of current supply external to the vehicle, a storage battery on said vehicle, a resistance, a propelling dynamo-electric machine on said Vehicle having two armature windings and one set of field windings, and means for connecting one of said armature windings to the storage battery in series with the field windings arranged in parallel or for connecting the other armature winding to the external source of supply in series with the field winding arranged in series, said means including a controller for connecting said resistance in circuit with either armature winding and gradually eliminating the resistance.

l1. In an electric traction system, a vehicle, a source of current supply external to the vehicle, astorage battery on said vehicle, a propelling dynamo-electric machine on said vehicle having two armature windings and one set of field windings, means for connecting one of said armature windings to the storage battery in series with the field windings arranged in parallel or for connecting the other armature winding to the external source oi supply in series with the field windings arranged in series, and means for automatically connecting one of said armature windings to the battery upon a predetermined voltage in that armature whenthe other armatureis connected to the externalsource. ,12. In combination,' a dynamo-electric machine having two armature windings and one set of field windings, two sources of current supply, and means for energizing one of said armature windings and .the field windings from one of said-sources or for energizing the other armature winding and the field order to cause said machine to operate.

13. In combination, a dynamo-electric machine having two armature windings and one set of field windings, two sources of current supply one of which is a storage battery, means for energizing one of said armature windings and the field windin s irom'one of said sources or for ener izing the other arnia ture winding-and the field windings from the other source in order to cause the machine to operate, and means for causing the o'nearmature winding to be automatically connected .to said storage battery at a predetermined voltage in that armature winding in order to charge the battery when the other armature winding and the field windings are being 011- ergized from theother source.

14. In an electric tract-ion system, a vehicle, a source of current supply eXte-rnalto the vehicle, a storage battery on said vehicle, a resistance, a propelling dynamoelectric ma chine on said vehicle having two'armatlrre windings and one set of field windings, means value of the current in the battery circuit during the charging of the battery.

15. In combination, a dynamo-electric machine having two armature windings and one set of field windings, a resistance, two sources of current supply, and means for energizing one of said armature windings and the field windings from one of said sources or for energizing the other armature winding and the field windings from the other source to cause said machine to operate, said means including a controller arranged to connect said resistance in circuit with either arma-' ture winding and to eliminate the resistance step by step. I i

16. In combination, a dynamo-electric machine having two armature windings and one set of field windings, two sources ol current supply, and means for connecting one armature in series with the field windings to one of said sources and for connecting the other. armature winding in series with the field windings to the other of said sources.

17. In combination, a dynamo-electric machine having two armature windings and one set of field windings, two sources of current supply one of which is a storage battery, and means for connecting one of said arm ature windings to the storage battery in series with the field windings arranged in parallel or for connecting the other armature winding to the other source of current supply in series with the field windings connected inscries.

18. In an electric traction system, a vehicle. a source of supply external to the vehicle, a storage battery on the vehicle, a dynamoelectric .machine on the vehicle having two armaturewindings and a single field winding.

means l or connecting one of said armature .wmdlngs and the field winding in series with each other to-the external source of supply to operate the vehicle, and connections from the other armature winding to the terminals of the storage battery for cl'iarging the battery while the vehicle is being propelled from the external source of current.

19. In an electric traction system, a vehicle, a source'of current sup pl y external to the vehicle, a. storage battery on the vehicle, a dynamo-electric machine on the vehicle hav- I mg two armature. windings and a single field vmeans iior connecting one of the winding, armaturewindings in series with the field winding to the external source of current supply l'c. propelling the vehicle, connections between the other armature winding and the In "witness whereof, I l mvehermmi-o $01 m hand th1s 31st day of May, 1906.

ALEXANDER CHUR CHWAH j Witnesses:

i ENJAlwllN B. HULL,

HELEN ORFORD. 

